An invertor device, an uninterruptible power supply, a machine tool, an industrial robot or the like use an independent semiconductor device (power semiconductor module).
As a conventional semiconductor device, a power module disclosed in Patent Document 1, for example, is known.
This power module includes, a power module substrate where a metal layer is bonded to both sides of a ceramic substrate, a heat sink, which is temporarily bonded to one of the metal layers via a temporarily sintered Ag layer, and a holding unit that holds the power module substrate and the heat sink in a stacked state.
Patent Document 1: Japanese Patent Application Laid-open No. 2012-114224